1. Field of the Invention
This invention relates to a method of producing a suspended agricultural chemical composition which is stable even after being preserved it for a long time.
2. Description of Related Art
In recent years, agricultural chemical active ingredients of high permeability have been developed and brought to market, and methods of coating seeds with them are generally used for controlling pests and disease. In order to ensure the safety of workers when coating the seeds, and to improve efficiency when coating the seeds, aqueous suspended formulations containing high-concentrations of agricultural chemical active ingredients are required. However, it is necessary to suppress Ostwald ripening causing crystal growth during a long term preservation, in order to produce aqueous suspended formulations containing high-concentrations of agricultural chemical active ingredients having a high solubility in water at room temperature. In Patent Literature 1, suspended agricultural chemical compositions, in which water-insoluble agricultural chemical active ingredients are dispersed in organic solvents having a high affinity with water and exerting significant solubilization effects on the agricultural chemical active ingredients, are disclosed. In Patent Literature 2, suspended agricultural chemical compositions, in which water-soluble active ingredients are dispersed in organic solvents having a high affinity with water and containing a low content of water, are disclosed. In Patent Literature 3, oil-in-water emulsive agricultural chemical compositions containing 0.1 to 2.0% by weight of hydrated alumina (as Al2O3) and 0.1 to 20% by weight of mineral salts are disclosed. In Patent Literature 4, agricultural chemical compositions containing organic acids, inorganic acids, and/or salts thereof are disclosed.    Patent Literature 1 Japanease Unexamined Patent Application, First Publication No. Sho 57-109701 (corresponding to U.S. Pat. No. 4,348,385)    Patent Literature 2 U.S. Pat. No. 5,906,962    Patent Literature 3 Japanease Unexamined Patent Application, First Publication No. Hei 5-25011    Patent Literature 4 Japanease Unexamined Patent Application, First Publication No.
However, the invention disclosed in Patent Literature 1 is limited to water-insoluble agricultural chemical active ingredients. The method disclosed in Patent Literature 2 causes problems, such as increase of the viscosity of products, which decreases the efficiency of discharging them from bottles. The invention disclosed in Patent Literature 3 relates to emulsions in which the agricultural chemical active ingredients are limited to aqueous organophosphorus ingredients. Patent Literature 4 has as its object to suppress decomposition of the agricultural chemical active ingredients during storage, and does not disclose any effects of inhibiting particle growth of active ingredients in the suspended agricultural chemical compositions.